Because the designer requested to do splicing, and here in Kuwait it is very hard to find either a mechanical connection to splice existing steel reinf to a new longer bar or to find a good reliable welder.
The only choice is to do splicing in traditional way , but if we did not follow the code...
Is it possible to splice (lap steel reinforcement ) the steel reinforcement in concrete column tie under tension load only , the splice length will meet the ACI codes . i.e no welding or mechanical connection to be used.